Pressure roll drives



Nov. 25, 1969 Filed Sept. 7. 1967 M. M. WHIPPLE PRESSURE ROLL DRIVES 5 Sheets-Sheet 1 snnnnnnnn MELVIN M. WHHPPLE l/VVE/VTGR Sac/(HORN, BLORE, KLAROU/ST a SPAR/(MAN ATTORNEYS Nqv. 25, 1969 M. M. WHIPPLE PRESSURE ROLL DRIVES 5 Sheets-Sheet 2 Filed Sept. 7, 1967 MELVIN M. WHIIPPLE INVE/VI'OI? BUC'KHORN, 51.095, KLAROU/ST a SPAR/(MAN ATTORNEYS 1969 M. M. WHIPPLE PRESSURE ROLL DRIVES 5 Sheets--Sheet 3 Filed Sept. 7. 1967 MELVIN M. WHIPPLE BUCKHOR/V, BAG/PE, KL/JRQU/ST 8 SPAR/(MAN ATTORNEYS Nov. 25, 1969 wmpp 3,480,653

PRESSURE ROLL DRIVES 5 Sheets-Sheet 4 Filed Sept. 7.- 1967 a k F 2 MELVIN M WHIPPLE 230 By INVENTOR &

BUG/(HORN, BLORE, KLAROU/ST a SPAR/(MAN l -228 ATTORNEYS United States Patent 3,480,053 PRESSURE ROLL DRIVES Melvin M. Whipple, 700 Delay Drive, Eugene, Oreg. 97402 Filed Sept. 7, 1967, Ser. No. 666,016 Int. Cl. B27l /02 US. Cl. 144-213 Claims ABSTRACT OF THE DISCLOSURE A pressure roll drive for a veneer lathe in which a gear rigidly fixed to a pressure roll is driven by a speedup gearing mounted on the side of the gear away from the log engaging chuck of the lathe.

This invention relates to improved pressure roll drives of veneer lathes, and more particularly to compact, high speed pressure roll drives of veneer lathes.

In veneer lathes known hitherto of the type having headstocks or chucks holding a log and rotating the log, together with a knife extending along the periphery of the log for cutting a veneer sheet from the log and a pressure roll supported by a strongback and engaging the portion of the log adjacent the knife, a hollow shaft receiving and connected to the pressure roll has been driven at one end of the lathe by a chain and sprocket. The shaft is supported in bearings at the sides of the sprockets. The pressure roll fits into and is rigidly locked or keyed to the shaft, which is larger in diameter than the pressure roll. This requires the bearings to be bulky, and the sprockets and chain on the shaft also are bulky. The extent to which a log can be turned down to form the veneer sheet is limited by the extent to which the pressure roll drive can be moved toward the chuck without being struck by the chuck, and the bulkiness caused by the chain and sprocket drive and the large bearings required because of the shaft of the prior art pressure roll drives has undesirably limited the extent that logs can be turned down. Also, with a chain and sprocket drive it has been impossible to get the speed of the periphery of the pressure roll anywhere near as fast as the normal operating speeds of the periphery of the log against which the pressure roll bears. As a result, there is undesired slippage between the log and the pressure roll. It would be desirable to provide a pressure roll drive which drives the pressure roll at a peripheral speed substantially as high as the peripheral speed of the log engaged by the pressure roll. It also would be desirable to provide a very compact, rugged, high speed pressure roll drive which permits movement of the pressure roll drive substantially closer to the adjacent chuck of the lathe so that much more veneer sheet can be obtained from each log.

An object of the invention is to provide new and improved pressure roll drives of veneer lathes.

Another object of the invention is to provide compact, high speed pressure roll drives of veneer lathes.

A further object of the invention is to provide a pressure roll drive of a veneer lathe which permits the pressure roll to be moved closer to the center of a log being turned than has hitherto been possible.

Yet another object of the invention is to provide a pressure roll drive of a veneer lathe which rotates the pressure roll at a high peripheral speed approximating the peripheral speed of a log being turned by the lathe.

Another object of the invention is to provide a pressure roll drive in which a pressure roll, a driven gear thereon and bearings supporting the pressure roll are very quickly removed from a bearing holding device and are quickly replaced by another pressure roll with its driven gear and bearings, so that the down time of the lathe is minimized.

Another object of the invention is to provide a pressure roll drive for a veneer lathe including a shaft carried by needle bearings and coupled to a pressure roll with ball thrust bearings engaging one end of the pressure roll and one end of the shaft.

A further object of the invention is to provide a pressure roll drive having an effective cooling system.

The invention provides improved pressure roll drives for veneer lathes, each drive including a driven gear coupled to a pressure roll carried by a strongback and driven by speedup gearing mounted on the strongback in a position at the side of the gear and pressure roll opposite to that at which the log and the log-engaging chuck of the lathe are positioned. The speedup gearing including a driven gear preferably is driven by a chain and sprocket driven by an electric motor. A pair of bearings positioned at opposite sides of the driven gear and journaling the driven gear preferably are mounted by a cap and a gear housing for the speedup gearing mounted on the strongback, the strongback preferably being pro vided with an offset portion mounting the housing.

A complete understanding of the invention may be obtained from the following detailed description of improved pressure roll drives for veneer lathes forming specific embodiments of the invention, when read in conjunction with the appended drawings, in which:

FIG. 1 is a fragmentary, top plan view of a veneer lathe having a pressure roll drive forming one embodiment of the invention;

FIG. 2 is a fragmentary vertical sectional view taken substantially along line 2-2 of FIG. 1;

FIG. 3 is an enlarged horizontal sectional view of the pressure roll drive of FIG. 1;

FIG. 4 is an enlarged vertical sectional view taken substantially along line 4-4 of FIG. 3;

FIG. 5 is an enlarged vertical sectional view taken substantially along line 5-5 of FIG. 3;

FIG. 6 is an enlarged vertical sectional view taken substantially along line 6-6 of FIG. 1;

FIG. 7 is an enlarged horizontal sectional view taken substantially along line 7-7 of FIG. 6;

FIG. 8 is an enlarged, fragmentary, horizontal sectional view of a pressure roll drive forming an alternate embodiment of the invention;

FIGS. 9, 10, 11, 12 and 13 are enlarged, fragmentary, vertical sectional views taken respectively along lines 99, 10-10, 11-11, 12-12 and 13-13 of FIG. 8 with the views inverted and FIG. 14 is a view of a pressure lubricator of the pressure roll drive of FIG. 8.

Referring noW in detail to the drawings, a veneer lathe shown in FIGS. 1 to 7 includes a headstock or chuck 10 rotating a log 12 from which a knife 14 (FIG. 2) cuts a thin, continuous veneer sheet 16. The knife 14 is mounted on and supported by carriage members 18 slidable on guide rods 20 and moved continuously inwardly toward the center of the log by feed screws 22, as is well known in the veneer lathe art. The carriage members support a strongback 24, and the strongback and a removable holding strip 26 thereon rotatably support a pressure roll 27 of Grade A Phosphor bronze in a position engaging the periphery of the log 12. The lathe chuck 10 (FIG. 1) is supported by a journaling and driving mechanism '28.

Duringthe slicing operation the strongback, the pressure,

roll and the knife are moved radially inwardly relative to the log by the feed screws 22 (FIG. 2) and the carriage members 18 which slide along the guide rods 20.

The pressure roll 27 is driven by a pressure roll drive 30 (FIG. 1). The drive 30 includes a strong, heavy bearing housing 31 which is secured on an offset portion 32 of the strongback 24 by bolts 34 (FIGS. 7 and 8), nuts 36 being threaded onto the ends of the bolts 34, and a liner 38 (FIG. 6) of babbitt metal mounting the housing 31 on the strongback 24. A guard plate or cap 40 is secured to the housing 31 by capscrews 42. A forked portion 37 of the housing 31 fits loosely over the offset portion 32 of the strongback 24, and the liner 38 is cast into and fits very snugly therebetween.

A pair of rugged flanged bushings (FIG. 3) journal the portions of the pressure roll 27 on opposite sides of a driven gear 54 rigidly locked and keyed to the pressure roll. The bushings 50 have end flanges 56 fitting against complementary portions 60 and 62, respectively, of the housing 31 and the cap 40, and fit into semicylindrical grooves 64 and 66 in the housing 31 and the cap 40. The bushings 50 are provided with radially extending keying portions 70, which fit into slots 74 in the cap 40. Spacer rings or shims are mounted on the pressure roll 27 on opposite sides of the gear 54 and prevent end play of the gear.

The gear 54 (FIG. 3) has an internal thread 84 formed therein which has an incompletely or only partially cut, tapered portion of about a of an inch in length, roughly about one-fifth of the length of the gear 54, formed near the lefthand end thereof, as viewed in FIG. 3, and the gear 54 is threaded onto a threaded portion 88 of the pressure roll 27, and the incompletely cut, tapered portion of the internal thread 84 jams onto the threaded portion 88 of the pressure roll to lock the gear 54 tightly onto the pressure roll with a jamming fit. After the gear 54 has been so threaded onto the pressure roll and jammed thereon, a portion 90 of the thread 88 is swaged to fill a short counterbore in the lefthand end of the gear 54, as viewed in FIG. 3, to further lock the gear 54 rigidly on the pressure roll. The threads of the gear 54 and the pressure roll are such that, as the driven gear 54 is driven to drive the pressure roll, the gear 54 tends to tighten onto the pressure roll and is prevented from moving further by the incompletely cut portion of the thread 84 so that a keying elfect is provided. The swaged portion 90 prevents turning of the gear in the other direction relative to the pressure roll. The pressure roll assembly comprising the pressure roll 27, the bushings 50, the shims 80 and the gear 54, may be inserted into the housing 31 and removed therefrom as a unit when the cap 40 is removed. This permits very quick removal of the pressure roll assembly and replacement thereof with a new. unworn pressure roll assembly.

The driven gear 54 (FIGS. 3, 6 and 7) is driven by a,

substantially larger drive gear having reduced shaft portions 101 and 103 journaled by radial and thrust bearings 102 mounted in aligned bores 104 and 106 in the housing 31 and secured therein by plugs 106 and 108 having holes 110 and 112 for spanner wrenches, the plug 106 completely closing threaded portion 114 of the bore 104, and the plug 108 being threaded into a threaded portion 116 of the bore 106 and being annular in shape to permit the shaft portion 103 to extend therethrough. The plug 108 is provided with a counterbore 120 receiving an oil seal 122 therein. A dual sprocket (FIGS. 1 and 7) secured by a setscrew 132 in a keying groove 134 in the shaft portion 103 is driven by chains 136 which mesh with sprocket portions 138 of the dual sprocket 130. The chains are driven by a dual sprocket 139 driven by an electric motor 140 carried by the carriage member 18. The gears 54 and 100 form a speedup gearing which makes the rotation of the pressure roll 27 a multiple of the rotation of the gear 100. The chains 136 and sprocket portions 138 I may. be large andv rugged. since theyare. well back, away from the chuck 10 (FIG. 1) and the journaling and driving mechanism 28 of the lathe. Also, the chains and sprocket can be driven at the maximum speed possible to efliciently drive the chains without wearing them out quickly, and, with the speedup gearing, the pressure roll can still be driven at a much higher speed than could be provided by a chain drive directly connected to the pressure roll without the speedup gearing positioned therebetween. The gears are of very tough steel of at least 180,000 pounds per square inch tensile strength.

To lubricate the gears 54 and 100, the bushings 50 and the bearings 102, the housing 31 is supplied with a lubricant under desired pressure by a pipe (not shown) leading to a supply of the lubricant under pressure. The lubricant fills the interior of the housing 31 and flows through radial grooves 152 (FIG. 4) and longitudinal grooves 154 in the bushings 50.

OPERATION In the operation of the veneer lathe shown in FIGS. 1 to 7, the chuck or headstock 10 (FIG. 1) is rotated to rotate the log. The knife 14 (FIG. 2) cuts the thin veneer sheet 16 from the log as the pressure roll 27 bears against the log and is roated by the pressure roll drive, and the feed screws 22 continuously move the carriage members 22 with the strongback 24 and pressure roll transversely of the log. The pressure roll is rotated by the motor 140 through the sprocket portions 139, the chains 140, the sprocket 130, the driving gear 100 and the driven gear 54. The gear 54 is mounted directly on the pressure roll and is small in diameter. The gear 54 fits closely in groove (FIG. 3) in the guard plate which is quite thin at this point so that there is a minimum space between the pressure roll and arcuate face 162 of the guard plate and the pressure roll may be moved much closer to the center of the log 12 than has been possible hitherto without engagement of the adjacent chuck 10 by the guard plate. Also, with the speedup gearing, which is mounted on the side of the pressure roll remote from the chuck 10 and the journaling and driving mechanism 28, the pressure roll is driven faster than is possible with previously known pressure roll drives. The pressure roll assembly may be removed and replaced very quickly with a minimum of down time of the lathe. If desired the gear 100 may have an over-running clutch therein to permit the pressure roll to be rotated faster than it is driven by the motor 140.

EMBODIMENT OF FIGS. 8 TO 14 A veneer lathe 210 shown in FIGS. 8 to 14 forming an alternate embodiment of the invention includes a headstock or chuck 210 and a tailstock 211 rotating a log 212 from which a knife (not shown) cuts a thin, continuous veneer sheet. The knife is mounted on and supported by carriage members slidable on guide rods and moved continuously inwardly toward the center of the log by feed screws similarly to the mounting and feed of the knife 12 (FIG. 2). The carriage members support a strongback 224 (FIG. 8) and the strongback and a removable holding strip 226 thereon rotatably support a pressure roll 227 of Grade A Phosphor bronze in a position engaging the periphery of the log 212. The strip 226 is secured to the strongback by capscrews 229 (FIG. 13) spaced therealong, and pairs of setscrews 231 screwed into bores 233 adjustably space the strip 226 from the strongback. The lathe chuck 210 (FIG. 1) is supported by a journaling and driving mechanism 228. During the slicing operation the strongback, the pressure roll and the knife are moved radially inwardly relative to the log by the feed screws.

The pressure roll 227 is driven by a pressure roll drive 230 (FIGS. 8-11). The drive 230 includes a strong, heavy bearing housing 231 rigidly mounted on an offset portion 232 of the strongback 224. A guard plate or cap 240 is secured to the housing 231 by capscrews 242. A forked portion 237 of the housing 231 fits loosely over the olfset portion 232 of the strongback, and a liner 238 is cast into the space therebetween. Capscrews 239 and setscrews 241 threaded into tapped bores 243 precisely position the housing on the strongback preparatory to casting the liner 238 in place.

The pressure roll drive 230 includes a driven gear 250 having a hardened gear portion 252 and reduced, aligned shaft ports 254 and 256. The shaft portion 256 has a square coupling or splining portion 258 which fits into a complementary socket 260 in a coupling sleeve 262 fitting tightly on a liner sleeve 263 tightly receiving the pressure roll 227. The liner sleeve 263 is fastened rigidly to the pressure roll and the coupling sleeve by a setscrew 264, and with the inner ends of the roll 227 and the liner sleeve 263 being swaged to enlarge the end portions and fit the roll tightly in the liner sleeve and the liner sleeve tightly in the coupling sleeve. There is some radial play or looseness, preferably about .010", between the sleeve 262 and the shaft portion 256 to isolate any flexing of the strongback from the shaft portion 256 and its journaling structure.

A notched or relieved portion 266 of the strongback 224 permits the sleeve 262 to be slid off the end of the shaft portion to permit removal of the pressure roll for replacement without disturbing the drive 230. The sleeve and pressure roll may be so disengaged after bolts 270 holding a thrust bearing block 272 on an end of the strongback are removed from tapped bores 273 in the end of the strongback. The bearing block 272 has a bore 274 normally aligned with and receiving the pressure roll and holding a carbide ball 276 seated in hardened spherical sockets 278 and 280 in the end of a steel extension 281 having a reduced shank portion 283 drive fitted into a bore 285 in the end portion of the pressure roll and the end of the bore 274. The ball 276 takes thrust of the pressure roll toward the top, as viewed in FIG. 8.

The shaft portion 256 is journaled in a needle bearing 290 seated in semicylindrical grooves 292 and 294 in the cap 240 and the housing 231, respectively. The needle bearing is restrained against endwise movement by arcuate flanges or ribs 296, 297, 298 and 299 of the cap and the bearing housing, respectively. The shaft portion 254 is journaled in a needle bearing 300 seated in semicylindrical grooves 302 and 304 respectively in the cap and the housing. The needle bearing abuts arcuate flanges or ribs 306 and 308 and also abuts a flange 310- of a bushing 312. The flange 310 fits in the grooves 302 and 304 with the body of the bushing fitting into and extending beyond smaller semicylindrical grooves 314 and'316 in the cap and the housing, respectively. The shaft portion 254 extends substantially to the bushing 312, and abuts a carbide ball 320 fitting in the bushing and abutting a hardened spherical end socket 322 in the end of the shaft portion and in a hardened spherical socket 324 in an end of a bore 326 in an arcuate plate 327 secured to the housing by screws 328. The balls 276 and 320 hold the gear 250 and the pressure roll 227 against endwise movement, the sleeve 262 abutting a reduced diameter portion 330 on the shaft portion 256. Thus, the gear 250 and the pressure roll are held strongly against thrust while the needle bearings 290 and 300' precisely journal the gear 250 radially and provide a very low friction, high speed mounting for the gear 250.

The gear 250 is driven by a hardened gear portion 338 of a driving gear 340 of twice the diameter of the gear 250 having shaft portions 342 and 344 and journaled in radial-and-thrust bearings 346 and 348 fitting in aligned bores 350 and 352 and constrained between plugs 354 and 358 threaded into tapped outer end portions of the respective bores 350 and 352. Setscrews 355 and 359 lock the plugs 354 and 358 in the bores 350 and 352. A sprocket 360 screwed onto a threaded portion 362 of the shaft portion 342 retains sealing rings 364 in a counterbore 366 in the plug 354. The sprocket 360 is driven by chains 368 driven by an electric motor (not shown) carried with the strongback 224.

To lubricate the needle bearings 290 and 300 and the balls 276 and 320, lubricant supply devices 380 supply lubricant through flexible conduits 386 and fittings 388. Passage portions 390 and 392 (FIG. 12) in the block 272 lead from one of the fittings 388 to the bore 274 in the block 272 to supply lubricant to the ball 276 and the bore 274. A blind, tapped bore 391 (FIG. 10) in the housing 231 receives lubricant under pressure from another of the fittings 388, and the lubricant flows as needed from the bore 391 through a branched passage 393 in the housing 231 and the cap 240 to a passage 395 in the arcuate plate 327 leading from the branch of the passage 393 to the bore 326 in the arcuate plate. The passage 393 also leads into an annular groove 398 (FIGS. 8 and 11) and the lubricant flows from the groove 398 through a hole 400 in the outer casing of the needle bearing 290 to the interior of the needle bearing 290. Similarly, the third fitting 388 which is shown in FIG. 9 supplies lubricant under pressure to a passage (not shown) in the housing 231 leading to an annular groove 396 (FIG. 8) through which the lubricant flows to a hole 402 in the outer casing of the needle bearing 300 and to the interior of the needle bearing 300. Passages 404 (FIG. 11) in the housing lead from annular groove portions 408 and 410 to portions 409 and 411 of the bores 350 and 352 at the outer ends of the bearings 346 and 348. Branch passages 416 and 418 (FIGS. 9 and 11) lead into central chamber 420 in the housing to supply lubricant to the gear portions 252 and 338. A rigid brace or hold-down arm 421 carried by one of the carriages carrying the strongback 224 engages a pad 423 and 'braces and steadies the strongback and the drive 230.

To provide cooling, a conduit 430 (FIG. 9) supplies cool water under a pressure of about five pounds per square inch from a suitable pressure source to the chamber 420 through a fitting 432 and a passage 434 in the housing. A small exit passage 436 in the housing 231 is directed upwardly and a spout of water is continuously emitted from the housing 231 to indicate to the operator that cooling is being effected. Similarly, a conduit 450 (FIG. 12) supplies cooling water continuously to a fitting 452 and a passage 454 in the block 272 to cool the block and the thrust bearing ball 276. The cooling water keeps the elements which are rotated relative to each other quite cool and the lubricants lubricate these elements for high speed operation.

The above-described pressure roll drives 30 and 230 drive the pressure rolls 27 and 227 at high speeds approaching the peripheral speeds of the logs 12 and 212, and are rugged and precise. The drive 230 is cooled and provides radial play between the shaft portion 256 and the sleeve 262 so that radial loading of the bearing 290 is minimized even if bowing of the strongback causes some misalignment of the shaft portion 256 and the pressure roll 227. The drives provide for maximum movement of the knives toward the center of the logs so that the resulting cores are minimum in diameter.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. In a pressure roll drive of a veneer lathe including chuck means,

a pressure roll,

movable strongback means journaling the pressure roll,

a rotatable driven gear member aligned with and keyed to the pressure roll for rotating the pressure roll,

a drive gear carried by the strongback means for rotating the driven member,

the driven gear member being positioned at one side of the chuck,

the drive gear being mounted in a position meshing with the driven gear member and at the side of the driven gear opposite to the chuck,

electric motor means carried with the strongback, and

coupling means coupling the electric motor means to the drive gear.

2. In a pressure roll drive for a veneer lathe including a chuck means, a carriage means, a strongback carried by the carriage means and a pressure roll carried by the strongback, the improvement comprising a housing carried by the strongback and open at the side thereof adjacent the chuck means, a cap closing said side of the housing, a driven gear of a predetermined diameter, first bearing means secured in the housing by the cap and mounting the driven gear in alignment with the pressure roll,

' means coupling the driven gear directly to the pressure roll,

a driving gear of a diameter substantially larger than that of the driven gear,

second bearing means mounting the driving gear rotatably in the housing in mesh with the driven gear and at the side of the driven gear opposite to the chuck means, and

means for driving the driving gear.

3. The pressure roll drive of claim 2 wherein the housing and the cap include aligned socket portions mounting the first bearing means and permitting removal of the first bearing means from the housing when the cap is removed from the housing.

4. The pressure roll drive of claim 2 wherein the housing includes a bore extending therethrough parallel to the pressure roll,

the driving gear having a central gear portion and shaft portions at opposite sides of the gear portion and positioned in the bore,

a pair of thrust bearings fitting in the end portions of the bore and journaling the shaft portions,

a plug closing one end of the bore and engaging one thrust bearing, and

an annular plug closing the other end of the bore and engaging the other thrust bearing.

5. The pressure roll drive of claim 4 including a sealing ring fitting into the annular plug.

6. The pressure roll drive of claim 5 including a sprocket secured to one of the shaft portions and holding the sealing ring in the annular plug.

7. In a pressure roll drive for a veneer lathe including a chuck means, a carriage means, a strongback carried by the carriage means and a pressure roll carried by the strongback, the improvement comprising a housing mounted on the strongback and having an attachment portion at one side thereof and open at the other side thereof and having spaced semi-annular socket portions at said other side, a pair of bearings adapted to fit into the semi-annular socket portions, a cap adapted to close said other side of the housing and retain the bearings in the socket portions, driven gear means journaled in the bearings, and coupled to the pressure roll, driving gear means in the housing and extending through the housing, bearing means in the housing mounting the driving gear means in mesh with the driven gear means, and driving means coupled to the driving gear means. 8. In a pressure roll drive for a veneer lathe including a pressure roll,

a strongback journaling the pressure roll, a knife, chuck means and carriage means for moving the strongback, the pressure roll and the knife toward a log carried by the chuck means, the improvement comprising:

housing means mounted on an end portion of the strongback,

a driven gear,

first bearing means radially journaling the driven gear in the housing means in alignment with the pressure roll,

means coupling the driven gear to the pressure roll,

first ball thrust bearing means mounted on the strongback in engagement with the end of the pressure roll remote from the driven gear,

second ball thrust bearing means mounted on the housing means in engagement with the end of the driven gear remote from the pressure roll,

a driving gear,

fourth bearing means journaling the driving gear in the housing means in mesh with the driven gear, and

means for driving the driving gear.

9. The pressure roll drive of claim 8 wherein the driven gear and the pressure roll are offset longitudinally from each other and the coupling means comprises a sleeve having a first end portion fixedly connected to the pressure roll and also having a second, splining end portion,

the driven gear being provided with a shaft portion having a splining end portion,

the splining end portions interfitting with a predetermined amount of radial play to accommodate misalignment of the pressure roll and the shaft portion.

10. The pressure roll drive of claim 8 wherein the first bearing means comprises a pair of needle bearlngs,

the driven gear including a gear portion and a pair of aligned shaft portions at opposite ends of the gear portion and journaled in the needle bearings.

11. The pressure roll drive of claim 10 wherein the housing means is split into a housing portion and a cap detachable from the housing portion, the needle bearings being secured between the cap and the housing portion.

12. The pressure roll drive of claim 11 wherein the second ball thrust bearing means includes a flanged bushing abutting one of the needle bearings, a ball in the bushing and a plate member secured to the housing means in engagement with the ball and holding the ball against the end of one of the shaft portions.

13. The pressure roll drive of claim 8 including pressure lubricating means, the housing means including a passage from the lubricating means to the first bearing means.

14. The pressure roll drive of claim 8 including means for supplying a coolant and passage means for carrying the coolant to the bearing means and gears,

15. The pressure roll drive of claim 14 wherein the passage means leads to the interior chamber of the housing means and the housing means is provided with an exit opening through which a spout of coolant flows in a position visible to an operator of the lathe.

References Cited UNITED STATES PATENTS 1,641,452 9/1927 Osgood 144-2l3 3,207,194 9/1965 Hedberg et a1. 144213 3,221,786 12/1965 Whipple l44209 DONALD R. SCHRAN, Primary Examiner 

